Kingdom of Thessalonica

The Kingdom of Thessalonica was a short-lived Crusader state in Greece which existed from 1204 to 1224, with Thessalonica serving as its capital. It was founded by Boniface of Montferrat in the aftermath of the Fourth Crusade, with Boniface claiming his own domain after he was passed over for leadership of the Latin Empire by Baldwin of Flanders. From 1204 to 1205, Boniface advanced into Thessaly, Boeotia, Euboea, and Attica. In 1207, he was ambushed and killed by Tsar Kaloyan of Bulgaria, and Lombard nobles dominated the kingdom as regents for his son Demetrius of Montferrat. In 1210, Michael I of Epirus and the Second Bulgarian Empire attacked the kingdom, and Theodore Komnenos Doukas, who succeeded Michael in 1214, conquered all of Thessalonica except the city itself. In 1224, Thessalonica fell to the Despotate of Epirus, which then formed the Empire of Thessalonica.